1. Field of the Invention
The present invention relates to a control apparatus-integrated dynamoelectric machine in which a control apparatus is mounted integrally to a dynamoelectric machine main body that has: a stator that has an armature winding; a rotor that has a field winding; and a housing that supports the stator and the rotor, the control apparatus controlling power supply to the armature winding and the field winding.
2. Description of the Related Art
Conventional dynamoelectric equipment includes: a rotor; a stator in which a polyphase winding is disposed; a shaft that supports the rotor so as to be centered on an axis of rotation; a supporting body to which the stator and the shaft are fixed; a heatsink that is integrated inside the supporting body; and control and field modules that control power supply to a field winding in the rotor, and power modules that control power supply to a stator winding in the stator that are respectively mounted to the heatsink (see Patent Literature 1, for example).
The control and field modules and the power modules (hereinafter “control modules”) each have switching elements, etc., of which metal oxide semiconductor (MOS) transistors or insulated gate bipolar transistors (IGBTs) are representative.
Although not described in Patent Literature 1 in detail, conventional examples of control modules that can be mounted to a heatsink and used are configurations in which switching elements that are mounted to a front surface of a heat spreader are sealed in a resin by transfer molding, in a similar manner to the semiconductor device according to Patent Literature 2. Here, the rear surface of the heat spreader, which constitutes a radiating surface, is exposed at a bottom surface of a resin package, and bottom surfaces of the control modules are constituted by the radiating surface of the heat spreader and the bottom surface of the resin package.
The heatsink has a flat base plate, and the control modules are mounted to one surface of the base plate (a heat receiving surface) such that radiating surfaces are coupled thermally, heat from the control modules thereby being transferred to the heatsink and radiated from the heatsink.    Patent Literature 1: Japanese Patent Publication No. 2008-543266 (Gazette)    Patent Literature 2: Japanese Patent Laid-Open No. 2003-7966 (Gazette)
In dynamoelectric equipment of this kind, the control modules are often mounted to the base plate so as to ensure electrical insulation between radiating surfaces thereof and the heat receiving surface of the base plate. In that case, the control modules are conventionally mounted to the heatsink with a thermally conductive grease or an electrically insulating sheet that has comparatively good thermal conductivity, such as that described in Patent Literature 2, interposed between the radiating surfaces of the control modules and the heat receiving surface of the base plate such that heat from the control modules is conducted to the base plate while ensuring electrical insulation between the control modules and the base plate.
Now, since the thermally conductive grease or the electrically insulating sheet have significantly inferior thermal conductivity compared with the heatsink, it is necessary to make the thickness of the thermally conductive grease or the electrically insulating sheet as thin as possible such that electrical insulation between the control modules and the base plate is ensured, and the heat from the control modules is also conducted smoothly to the base plate. Conventionally, the thermally conductive grease or the electrically insulating sheet is interposed between the control modules and the base plate by making the bottom surfaces of the control modules as flat as possible, and making the heat receiving surface of the base plate flat by applying milling, but milling of the heatsink is very expensive.
Now, when dynamoelectric equipment of this kind is mass-produced, the heatsinks are conventionally prepared by die casting for purposes of cost reduction. In heatsinks that are prepared using die casting, it is known that baseplate thickness differs during formation such that mainly central portions are concave. Moreover, centers of the base plates are not necessarily the deepest portions.
The front surface shape of the heat receiving surface differs depending on location. In other words, because the portions of the heat receiving surface to which the control modules are mounted are not uniform, it is necessary to prepare shapes of bottom surfaces of each of the control modules so as to have shapes of the mounting portions of the corresponding heat receiving surfaces. In other words, the shapes of the bottom surfaces of a plurality of control modules must be made into different shapes. Consequently, a plurality of control modules that are transfer molded using molds that have identical shapes cannot be used, increasing costs for the control modules. If the heat receiving surface of the base plates is made to conform to the shape of the radiating surfaces of the control modules by applying milling to the heat receiving surface, even though increasing thickness of the thermally conductive grease or the electrically insulating sheet can be avoided, problems such as great expense being required for milling of the base plates, etc., resurface.